https://github.com/stuaxo/shoebot-scenegraph-experiment

Building a scenegraph based graphics engine for shoebot
https://github.com/stuaxo/shoebot-scenegraph-experiment

Last synced: about 6 hours ago
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Building a scenegraph based graphics engine for shoebot

• Host: GitHub
• URL: https://github.com/stuaxo/shoebot-scenegraph-experiment
• Owner: stuaxo
• Created: 2014-06-02T09:22:29.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-11-18T22:00:51.000Z (almost 10 years ago)
• Last Synced: 2024-10-13T01:28:34.305Z (about 1 month ago)
• Language: Python
• Size: 184 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
Scenegraph renderer experiment.

Implements a simple nodebox/shoebot like grammar end renders using a scenegraph.

Example, rendering to cairo.

```python

import cairocffi as cairo

import drivers.cairo

from scenegraph import *

if __name__=="__main__":

    c = Canvas()

    c.fill("blue")

    c.stroke(0, 1, 0)

    

    p = c.path()

    p.moveto(0, 0)

    p.lineto(100, 0)

    p.lineto(100, 100)

    p.lineto(0, 100)

    p.lineto(0, 0)

    # Render to a cairo surface

    surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 200, 200)

    ctx = cairo.Context(surface)

    drivers.cairo.render(c.scenegraph, ctx)

    

    surface.write_to_png("output.png")

    # Display the graph we just rendered

    debug(c)

```

The simple commands, add elements to the scenegraph, for instance - the example 

above creates the following scenegraph:

```

 

     

     

     

         

         

         

         

            

```

Drivers render the graph by traversing it and instanciating classes that mirror 

those in the scenegraph, but that can do the rendering.

Finding classes:

================

In the cairo driver, classes are nested, the TraverserMixn can find the

implementation by looking inside the child class.

```python

class Canvas(TraverserMixin):

    ....

    class Path(TraverserMixin):

        class PathElement(CmdMxin):

            def lineto(self, traverser, x, y):

                traverser.ctx.line_to(x, y)

            def moveto(self, traverser, x, y):

                traverser.ctx.move_to(x, y)

            def rect(self, traverser, width, height):

                traverser.ctx.rectangle(0, 0, width, height)

```

Commands

--------

In the code above some PathElement is a CmdMixin - this allows functions to be

used.

TODO

====

State passed around needs to be much more simple.